Integrating medical data at inter-centre level implies many challenges that are being tackled from many disciplines and technologies. Medical informatics have applied an important effort on describing and standardizing Electronic Health Records, and specially standardisation has achieved an important extent on Medical Imaging. Grid technologies have been extensively used to deal with multi-domain authorisation issues and to provide single access points for accessing DICOM Medical Images, enabling the access and processing to large repositories of data. However, this approach introduces the challenge of efficiently organising data according to their relevance and interest, in which the medical report is a key factor. The present work shows an approach to efficiently code radiology reports to enable the multi-centre federation of data resources. This approach follows the tree-like structure of DICOM-SR reports in a self-organising metadata catalogue based on AMGA. This approach enables federating different but compatible distributed repositories, automatically reconfiguring the database structure, and preserving the autonomy of each centre in defining the template. Tools developed so far and some performance results are provided to prove the effectiveness of the approach.